Polyelectrolyte membranes as separator for battery and fuel cell applications

Abstract

Herein provided are polyelectrolyte membranes that block dendrite growth in rechargeable batteries, possess low inherent electrical resistance to be used as separators, possess high ionic conductivities, and block fuel crossover in direct fuel feeding fuel cells. Further provided are cost-effective processes for forming polyelectrolyte membranes. The herein described polyelectrolyte membranes are useful in electrochemical cells such as primary batteries, secondary batteries such as Ag—Zn, Ni—Zn, Ni-MH, Li polymer, and Li-ion; fuel cells including but not limited to metal air battery or fuel cells, proton exchange membrane hydrogen fuel cells, direct liquid feed fuel cell.

1 . A membrane for an electrochemical cell comprising: 
 at least one pair of oppositely charged membranes including a polyanion membrane and adjacent a polycation membrane, wherein electrical double layers are formed at the interface of the polyanion and polycation membranes.    
     
     
         2 . An electrochemical cell comprising the membrane of  claim 1 .  
     
     
         3 . The membrane as in  claim 1 , wherein plural, pairs of oppositely charged membranes are provided adjacent one another.  
     
     
         4 . The membrane as in  claim 1 , wherein at least one of the polyanion membrane or the polycation membrane includes a neutral polymer.  
     
     
         5 . The membrane as in  claim 1 , wherein an anionic polymer forming the polyanion membrane is selected from the group consisting of poly(sodium styrene sulfonate). poly(acrylic acid) sodium salt, poly(acrylic acid)-co-polymers, (poly(styrene-co-sodium styrencsulfonate), poly(sulfone-co-sodium sulfonate), poly(ethy acrylate-co-sodium acrylate), poly(butadiene-co-lithium, methacrylate), poly(ethylene-co-sodium methacrylate), poly(ethylene-co-magnesium methacrylate), zinc-sulfonated ethylene-propylen-terpolymer carboxymethyl cellulose sodium salt, Nafion, and other suitable polyanions.  
     
     
         6 . The membrane as in  claim 1 , wherein an anionic polymer forming the polyanion membrane has the structure  
       
         
           
           
               
               
           
         
       
       wherein M is selected from the group consisting of Na + , Li + , K + , Zn 2+ , Mg 2+ , Al 3+ , Cu 2+ , Ag + , Ni 2+ .  
     
     
         7 . The membrane as in  claim 1 , wherein an anionic polymer forming the polyanion membrane has the structure  
       
         
           
           
               
               
           
         
       
       wherein M is selected from the group consisting of Na + , Li + , K + , Zn 2+ , Mg 2+ , Al 3+ , Cu 2+ , Ag + , Ni 2+ .  
     
     
         8 . The membrane as in  claim 1 , wherein an cationic polymer forming the polycaiton membrane is selected from the group consisting of poly(diallyldimethylammonium chloride). Poly(N-methyl-4-vinylpyridinium iodide), poly(allylamine hydrochloride), poly(butyl acrylate-co-N-methyl-4-vinylpyridinium iodide), poly(butadiene-co-N-methyl-4-vinnylpyridinium) iodide, poly(styrene-co-4-vinylpyridine), poly(ethyl acrylate-co-4-vinylpyridine), polyaniline-based polymers, polypyrrole-base polymers, and other suitable polycations.  
     
     
         9 . The membrane as in  claim 1 , wherein an cationic polymer forming the polycaiton membrane has the structure  
       
         
           
           
               
               
           
         
       
       wherein R1 is selected from the group consisting of -Ch3, —CH2CH3, —CH2CH2CH3, —(CH2) n CH3, R2 is _—CH3, —CH2CH3, —CH2CH2CH3, —(CH2) n CH3; X is Cl − , Br − , I − , F − , CO3 2− , SO4 2− , PO4 3− .  
     
     
         10 . The membrane as in  claim 1 , wherein an cationic polymer forming the polycaiton membrane has the structure  
       
         
           
           
               
               
           
         
       
       wherein R is selected from the group consisting of —CH3, —CH2CH3, —CH2CH2CH3, —(CH2) n CH3, X is Cl − , Br − , I − , F − , CO3 2− , SO4 2− , PO4 3− .  
     
     
         11 . The membrane as in  claim 4 , wherein the neutral polymer is selected from the group consisting of PVA, PEO, PVDF, PPO, PA, PEA, PEEK, PET, PMMA, poly2,6-dimethyl-1,4-phenylene odixe), poly2,6-diphenyl-1,4-phenylene oxide), and poly(4-vinylpyridine).  
     
     
         12 . The membrane as in  claim 1 , wherein the polyanion and polycation are formed on a substrate.  
     
     
         13 . The membrane as in  claim 12 , wherein the substrate is a porous substrate.  
     
     
         14 . The membrane as in  claim 13 , wherein the porous substrate comprises nylon or polypropylene.  
     
     
         15 . The membrane as in  claim 1 , wherein the electrochemical cell comprises a secondary battery, and the membrane protects the secondary battery from dendrite related ineffectiveness.  
     
     
         16 . The membrane as in  claim 1 , wherein the electrochemical cell comprises a direct fuel feed fuel cell, and the membrane protects the direct fuel feed fuel cell from fuel crossover.